The term "sod" refers to a piece or section of grass, typically sold in rolls or squares for use as lawn cover. It can also refer to the top layer of soil and its associated organic matter, which is often removed and replaced with fresh soil when preparing a site for landscaping or construction. In addition, "sod" can be used as an idiomatic expression meaning something that has been done before or is considered routine, such as "giving the same old song and dance."